The races of Men are pretty easy to figure out - I mean saying Nords are based off the Norse is like saying the sky is blue - the interesting thing to me is analysing aspects of the nonhuman races. A lot of different things go into the identity of mer and beastfolk, some of which don't necessarily reflect any particular real-life culture in my opinion.
In dunmer for example we can see a lot of ideas from different cultures. The architecture for example is heavily reminiscent of Mesopotamian architecture, in the sense that its made of sandstone, mudstone etc. The cantons could be likened in ways to the pyramids of Egypt, or Babylonian zuggurats. Over all, the intended feeling is to evoke an ancient Levantine society, so the player gets a real sense not just of the Dunmers exotic culture but also the ancient and longstanding history of the Velothi people.
The most interesting group (to me) are the Ashlanders, who borrow cultural keystones from a wide variety of eastern cultures. Their penchant for prophecy and their history of religious persecution is very reminiscent of the Semitic peoples, whereas their nomadic nature could borrow from other real life groups, such as the bedouin.
As someone who writes(for fun, sometimes) and enjoys above all else worldbuilding, the key intent with such real-life connections is so that the theme of the race sticks with the reader, or in this circumstance, player. Hence why Cyrodiil is based off the Romans (people have an understanding that Roman = civilised). Although some might decry it as unoriginal (at the very least, I've heard these things before) the truth is that it is simply impossible to write anything truly "original". Everything is derivative, at least to some extent.
Wood Elves borrow from Native American culture, although I would argue this is mostly in philosophy rather than any sense of aesthetic or culture. My knowledge of Native American people is very slight to say anything more but the idea of living in unison with the land is very reminiscent of the cultures of early America. However. Mostly I believe their design is borrowed not from real life but rather a derivative of Dungeons and Dragons - the fantasy setting which first distinguished elves into Dark, Wood, and High/Sun. Prior, Tolkien had of course separated his elves into different bloodlines, which Dungeons and Dragons would be inspired by. Its from this genesis where the typical trappings of the wood elves come, and of the Elder Scrolls the wood elves are the most "typical" of elves in my opinion. This is probably compounded by my lack of interest in wood elves, and hence a lack of knowledge about them.
The Wild Hunt is inspired by European Mythology of the same name; beyond that, however, the resemblance ceases. The Wild Hunt has inspired many such things in fantasy, and as such it has become conceptually diluted. The only commonality between the wild hunt of TES, the Witcher, and Warhammer is that they're parties of savage hunters, with revenge being a loose theme.
For Argonians the inspiration is far more direct. Their temples and buildings are heavily inspired by Mesoamerican structures, stone pyramids and mudstone huts. This may be a byproduct of their environs; similarly to South America, Black Marsh is mostly - well, marsh - also jungles and wetland. Again though, their culture is more abstract and harder to define than their materialculture. As far as I'm aware there have been no cases of trees mind controlling lizardfolk to their service, although that does make me wonder if the Argonians share too some heritage from real-life from Natuve Americans. Not in the sense they are directed by trees, but rather in their ties to the land, which was a large part of Native culture.
The Khajiit share many cultural links with Middle Eastern cultures. Moreso than Ashlanders they share Bedouin inspiration, and generally they have are represented by an Arabic aesthetic indicative of their homeland, after all Elsweyr is roughly 50% desert and 50% jungle. There could be some Indian inspiration, or perhaps even Semitic (with their rather prophetic beliefs around things like the Mane). Indian inspiration could come from a quasi-caste system the Khajiit have, specifically with their different breeds fulfilling different roles in society.
High Elves are probably one of the most "un-real" of races, due to their culture revolving around things that don't exist. Magic isn't real... at least I think it's not real... which makes Altmer pretty interesting.
Obviously their history is reminiscent of Atlantean myth, with Aldmeris being a grand civilisation that was lost. The modern thalmor share a LOT of similarities with a uh... certain German political party of the 20th century, particularly with their abolishment of the Altmer monarchy, belief in the superiority of their race above others, and extreme militarist bearing. Even in sense of style, thalmor agents parallell their real-life counterparts, wearing sleek black robes, imposing and rather alien when compared to the rugged garb of men. It's a strange blend of different styles which come together in order to make a race that is supposed to be suitably alien and exotic.